Communication system for use with train consist

ABSTRACT

The disclosure is directed to a communication method for use with a train consist having a locomotive and a tender car. The communication method may include transmitting between the locomotive and the tender car operational data captured by network components located onboard at least one of the locomotive and the tender car. The method may further include selectively adjusting an operation of at least one of the locomotive and the tender car based on the data.

TECHNICAL FIELD

The present disclosure relates generally to a communication method and,more particularly, to a communication method for use with a trainconsist.

BACKGROUND

A consist includes one or more locomotives, and in some instances atender car, that are coupled together to produce motive power for atrain of rail vehicles. The locomotives each include one or moreengines, which combust fuel to produce mechanical power. The engine(s)of each locomotive can be supplied with liquid fuel (e.g., diesel fuel)from an onboard tank, gaseous fuel (e.g., natural gas) from the tendercar, or a blend of the liquid and gaseous fuels. The mechanical powerproduced by the combustion process is directed through a generator andused to generate electricity. The electricity is then routed to tractionmotors of the locomotives, thereby generating torque that propels thetrain. The locomotives can be connected together at the front of thetrain or separated and located at different positions along the train.For example, individual locomotives can be located at either end of thetender car, and the consist can be positioned at the front, middle, orend of the train. In some instances, more than one consist may beincluded within a single train.

Because the locomotives of a consist must cooperate to propel the train,communication between the locomotives and/or between the locomotives andthe tender car can be important. Historically, this communication hasbeen facilitated through the use of an MU (Multi-Unit) cable thatextends along the length of the consist. An MU cable is comprised ofmany different wires, each capable of carrying a discrete signal used toregulate a different aspect of consist operation. For example, a leadlocomotive generates current within a particular one of the wires toindicate a power level setting requested by the train operator. Whenthis wire is energized, the engines of all locomotives are caused tooperate at a specific throttle value. In another example, when onelocomotive experiences a fault condition, another of the wires isenergized to alert the other locomotives of the condition's existence.

Although acceptable in some applications, the information traditionallytransmitted via the MU cable may be insufficient in other application.For example, during the fault condition described above, it can beimportant to know a severity and/or cause of the fault condition so thatan appropriate response to the fault condition can be implemented in aneffective and efficient manner. Additionally, as consist configurationsbecome more complex, for example during multi-unit blended fueloperations (i.e., operations where gaseous fuel from the tender car issimultaneously supplied to multiple locomotives and mixed with dieselfuel at different rates), control of the locomotives and/or the tendercar may require a greater amount of cooperation and/or more complexcommunication than can be provided via the MU cable.

One attempt to address the above-described problems is disclosed in U.S.Patent Publication 2010/0241295 of Cooper et al. that published on Sep.23, 2010 (“the '295 publication”). Specifically, the '295 publicationdiscloses a method of communicating a lead locomotive and one or moretrail locomotives with each other via an MU cable. Each locomotiveincludes a computer unit, which, along with the MU cable, forms anEthernet network in the train. With this configuration, network data canbe transmitted from the computer unit in the lead locomotive to thecomputer units in the trail locomotives. The network data includes datathat is packaged in packet form as data packets and uniquely addressedto particular computer units. The network data can be vehicle sensordata indicative of vehicle health, commodity condition data, temperaturedata, weight data, and security data. The network data is transmittedorthogonal to conventional non-network (i.e., command) data that isalready being transmitted on the MU cable.

While the consist of the '295 publication may have improvedcommunication between locomotives, it may still be less than optimal. Inparticular, the disclosed method of the '295 patent may not have aneffect on control over tender car/locomotive operations.

The methods of the present disclosure solve one or more of the problemsset forth above and/or other problems with existing technologies.

SUMMARY

In one aspect, the disclosure is directed to a method of communicating alocomotive with a tender car. The method may include transmittingbetween the locomotive and the tender car operational data captured bynetwork components located onboard at least one of the locomotive andthe tender car. The method may further include selectively adjusting anoperation of at least one of the locomotive and the tender car based onthe data.

In another aspect, the disclosure is directed to another method ofcommunicating a locomotive with a tender car. This method may includetransmitting identification information between the locomotive and thetender car, and making a determination of an incompatibility between thelocomotive and the tender car based on the identification information.The method may further include generating an alert based on thedetermination.

In yet another aspect, the disclosure is directed to still anothermethod of communicating a locomotive with a tender car. This method mayinclude transmitting identification information between the locomotiveand the tender car, and making a determination of a discrepancy betweena capacity of the locomotive and a capacity of the tender car based onthe identification information. The method may further include scalingfuture operation of at least one of the locomotive and the tender carbased on the determination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial illustration of an exemplary disclosed consist;and

FIG. 2 is a diagrammatic illustration of an exemplary disclosedcommunication system that may be used in conjunction with the consist ofFIG. 1.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary train consist 10 having one or morelocomotives 12 and a tender car 14. In the disclosed embodiment, consist10 has three different locomotives 12, including a lead locomotive 12 alocated ahead of tender car 14 and two trailing locomotives 12 b, 12 clocated behind tender car 14. It is contemplated, however, that consist10 may include any number of locomotives 12 and/or tender cars, and thatlocomotives 12 may be located in any arrangement relative to tendercar(s) 14 and in any orientation (e.g., forward-facing or rear-facing).Consist 10 may be located at the front of a train of other rail vehicles(not shown), within the train of rail vehicles, or at the end of thetrain of rail vehicles. It is also contemplated that more than oneconsist 10 may be included within a single train of rail vehicles, ifdesired, and/or that consist 10 may travel at times without a train ofother rail vehicles.

Each locomotive 12 may be connected to an adjacent locomotive 12 and/ortender car 14 in several different ways. For example, locomotives 12 andtender car 14 may be connected to each other via a mechanical coupling16, one or more fluid couplings 18, and one or more electrical couplings20. Mechanical coupling 16 may be configured to transmit tractive andbraking forces between locomotives 12 and tender car 14. Fluid couplings18 may be configured to transmit fluids (e.g., fuel, coolant,lubrication, pressurized air, etc.) between locomotives 12 and tendercar 14. Electrical couplings 20 may be configured to transmit powerand/or data (e.g., data in the form of electrical signals) betweenlocomotives 12 and tender car 14. In one example, electrical couplings20 include an MU cable configured to transmit conventional commandsignals and/or electrical power. In another example, electricalcouplings 20 include a dedicated data link configured to transmitpackets of data (e.g., Ethernet data), as will be discussed in moredetail below. In yet another example, the data packets may betransmitted via the MU cable. It is also contemplated that some data maybe transmitted between locomotives 12 and tender car 14 via acombination of the MU cable, the dedicated data link, and/or other means(e.g., wirelessly), if desired.

Each locomotive 12 may include a car body 22 supported at opposing endsby a plurality of trucks 24 (e.g., two trucks 24). Each truck 24 may beconfigured to engage a track (not shown) via a plurality of wheels, andto support a frame 26 of car body 22. Any number of engines 28 may bemounted to frame 26 within car body 22 and drivingly connected to agenerator 30 to produce electricity that propels the wheels of eachtruck 24. Engines 28 may be internal combustion engines configured tocombust a mixture of air and fuel. The fuel may include a liquid fuel(e.g., diesel) provided to engines 28 from a tank 32 located onboardeach locomotive 12, a gaseous fuel (e.g., natural gas) provided bytender car 14 via fluid couplings 18, and/or a blended mixture of theliquid and gaseous fuels.

Tender car 14, like locomotives 12, may also be equipped with a frame 26that is supported by two or more trucks 24. Tender car 14 may alsoinclude one or more tanks 34 mounted to its frame 26 that are configuredto store liquefied gaseous fuel (e.g., liquefied natural gas or LNG).The liquefied gaseous fuel may be gasified and then fed in series orparallel to all locomotives 12 of consist 10 for combustion withinengines 28. In the disclosed embodiment, a single insulated tank 34 isused to store the liquefied gaseous fuel at low temperatures, such asbelow about −160° C. In some embodiments, tank 34 may be integral withframe 26 of tender car 14.

Additional fuel delivery components may be associated with tender car 14and used to gasify and/or transport the fuel from tender car 14 tolocomotives 12. These components may include, among other things, one ormore fuel pumps 36, one or more heat exchangers 38, one or moreaccumulators 40, one or more regulators 42, and associated conduits (notshown) that condition, pressurize or otherwise move fuel, as is known inthe art.

Pump(s) 36 may be situated near or within tank 34, and embody, forexample, cryogenic pumps, piston pumps, centrifugal pumps, or any otherpumps that are known in the industry. Pumps 36 may primarily be poweredwith electricity supplied via couplings 20 from generators 30 locatedonboard locomotives 12 (e.g., onboard lead locomotive 12 a).Additionally or alternatively, pumps 36 may be powered by an electricstorage system and/or an onboard auxiliary engine (not shown), ifdesired. Pumps 36 may pressurize the liquefied gaseous fuel to a desiredoperating pressure and push the fuel through heat exchanger(s) 38 toaccumulator(s) 40. Heat exchanger(s) 38 may provide heat sufficient togasify the fuel as it moves therethrough. Upon vaporization, the fuelmay be transported to and stored within accumulator(s) 42. Althoughshown as being located onboard only tender car 14, it is contemplatedthat some or all of accumulator(s) 42 could alternatively be locatedonboard each locomotive 12. Gaseous fuel may be directed to engines 28via regulator(s) 42.

As shown in FIG. 2, consist 10 may be equipped with a communicationsystem 44 that facilitates coordinated control of locomotives 12 andtender car 14. Communication system 44 may include, among other things,an access point 46 for each locomotive 12 and for tender car 14. Eachaccess point 46 may be connected to one or more wired and/or wirelessnetworks, and used to communicate command signals and/or data betweencontrollers 48 of each rail vehicle and various other network components(e.g., sensor, valves, pumps, heat exchangers, accumulators, regulators,actuators, etc.) 50 that are used to control locomotives 12 and/ortender car 14. Access points 46 may be connected to each other viaelectrical couplings 20 (e.g., via the MU cable, via the dedicated datalink, and/or wirelessly).

Each access point 46 may include a processor, a router & bridge, an MUmodem, input/output (I/O) ports, a storage, a memory, and any otherconventional components known in the art. The I/O ports may facilitatecommunication between the associated access point 46 and one or more ofnetwork components 50. Likewise, the MU modem may facilitatecommunication between different access points 46 connected to each othervia electrical couplings 20. The router & bridge may be configured toroute data packets between the processor and the I/O ports and/orbetween the processor and the MU modem. For example, when a particularaccess point 46 receives data packets from corresponding I/O portsand/or from the MU modem, the router & bridge may route the data packetsto the processor.

The processor may include one or more processing devices, such asmicroprocessors and/or embedded controllers. The storage may includevolatile or non-volatile, magnetic, semiconductor, tape, optical,removable, non-removable, or other type of computer-readable medium orcomputer-readable storage device. The storage may be configured to storeprograms and/or other information that may be used to implement one ormore of the processes discussed below. The memory may include one ormore storage devices configured to store information used by theassociated access point 46.

Each controller 48 may be configured to control operational aspects ofits related rail vehicle. For example, controller 48 of lead locomotive12 a may be configured to control operational aspects of itscorresponding engine 28, generator 30, traction motors, operatordisplays, and other associated components. Likewise, the controllers 48of trail locomotives 12 b and 12 c may be configured to controloperational aspects of their corresponding engines 28, generators 30,traction motors, operator displays, and other associated components. Insome embodiments, controller 48 of lead locomotive may be furtherconfigured to control operational aspects of trail locomotives 12 b and12 c, if desired. Controller 48 of tender car 14 may be configured tocontrol operational aspects of pump(s) 36, heat exchanger(s) 38,accumulator(s) 40, regulator(s) 42, and other associated tender carcomponents.

Each controller 48 may embody a single microprocessor or multiplemicroprocessors that include a means for controlling an operation of theassociated rail vehicle based on information obtained from any number ofnetwork components 50 and/or communications received via access points46. Numerous commercially available microprocessors can be configured toperform the functions of controller 48. Controller 48 may include amemory, a secondary storage device, a processor, and any othercomponents for running an application. Various other circuits may beassociated with controller 48 such as power supply circuitry, signalconditioning circuitry, solenoid driver circuitry, and other types ofcircuitry.

The information obtained by a particular controller 48 via access points46 and/or network components 50 may include performance related dataassociated with operations of each locomotive 12 and/or tender car 14(“operational information”). For example, the sensory data could includeengine related parameters (e.g., speeds, temperatures, pressures, flowrates, etc.), generator related parameters (e.g., speeds, temperatures,voltages, currents, etc.), operator related parameters (e.g., desiredspeeds, desired fuel settings, locations, destinations, braking, etc.),liquid fuel related parameters (e.g., temperatures, consumption rates,fuel levels, demand, etc.), gaseous fuel related parameters (e.g.,temperatures, supply rates, fuel levels, etc.), and other parametersknown in the art. The performance related data may be data sensed viaindividual sensors of network components 50 and/or data that iscalculated based on assumed or measured parameters.

The information obtained by a particular controller 48 via access points46 and/or network components 50 may also include identification data ofthe other rail vehicles within the same consist 10. For example, eachcontroller 48 may include stored in its memory the identification of theparticular rail vehicle with which controller 48 is associated. Theidentification data may include, among other things, a type of railvehicle (e.g., make, model, and unique identification number), physicalattributes of the associated rail vehicle (e.g., size, load limit,volume, power output, power requirements, fuel consumption capacity,fuel supply capacity, etc.), and maintenance information (e.g.,maintenance history, time until next scheduled maintenance, usagehistory, etc.). When coupled with other rail vehicles within aparticular consist 10, each controller 48 may be configured tocommunicate the identification data to the other controllers 48 withinthe same consist 10. Each controller 48, as will be described in moredetail below, may be configured to selectively affect operation of itsown rail vehicle based on the obtained identification data associatedwith the other rail vehicles of consist 10.

In some embodiments, controllers 48 may each be configured to affectoperation of their associated rail vehicles based on the informationobtained via access points 46 and/or network components 50 and one ormore maps stored in memory. Each of these maps may include a collectionof data in the form of tables, graphs, and/or equations. Some of theseoperations will be described in more detail in the following section.

In some instances, it may be beneficial to export operationalinformation to an offboard entity 52. In particular, lead locomotive 12a (or another rail vehicle of the associated consist 10) may be equippedwith a communication device 54 connectable with controller 48.Communication device 54 may be configured to communicate messageswirelessly between controller 48 and offboard entity 52. The wirelesscommunications may include satellite, cellular, infrared, and any othertype of wireless communication. Offboard entity 52 may be, for example,service personnel, and the communications may include messages regardingfault conditions, identification of failed components, and/orinstructions for the service personnel. It is contemplated that otherinformation may also be transmitted offboard, if desired.

INDUSTRIAL APPLICABILITY

The disclosed communication system may be applicable to any consisthaving at least one locomotive and a tender car that is coupled with thelocomotive. The communication system may enhance cooperation between thelocomotive and the tender car by facilitating complex communication ofdata that affects fuel use and fuel supply. Exemplary operations ofcommunication system 44 will now be described in detail.

As disclosed above, during or after coupling of different rail vehicleswithin a particular consist 10, controllers 48 of each rail vehicle maybegin to communicate with each other via electrical couplings 20. Forexample, controller 48 of tender car 14 may communicate with eachcontroller 48 of locomotives 12 via the existing MU cable. Thiscommunication may include the exchange of identification information.For instance, controller 48 of tender car 14 may provide the othercontrollers 48 of each locomotive 12 with an identification of tendercar 14 as a tender car of a particular make and model. Controller 48 oftender car 14 may additionally communicate a maximum fuel volume, a fuelsupply capacity, an electrical power requirement, a maintenance history,and other information to locomotives 12. In some instances, controllers48 of locomotives 12 may already know some of this information based onthe make and model of tender car 14. Likewise, controllers 48 oflocomotives 12 may transmit similar information to tender car 14 at thissame time.

In some embodiments, controllers 48 of the different rail vehicles mayadjust operation of their associated rail vehicles based on theidentification information. For example, it may be possible that one ormore rail vehicles of particular makes and models are not compatiblewith each other. And after the exchange of identification information,an alert may be generated indicative of the situation. In anotherexample, it may be possible for a particular locomotive 12 (or group oflocomotives 12) to normally demand a fuel supply rate during aparticular throttle setting that exceeds an established capacity oftender car 14 to supply fuel. In this situation and based on theidentification information, controllers 48 of one or more of locomotives12 may be configured to selectively scale future fuel supply demandswhile connected with the particular tender car 14. For the purposes ofthis disclosure, scaling may be considered a reduction or increase in ademand for fuel from for particular engine 28 according to one or morescale factors stored in memory and associated with particular makesand/or models of tender cars 14. Alternatively, controllers 48 of one ormore of locomotives 12 may be configured to selectively use differentfuel blend ratios. It may also be possible for controllers 48 oflocomotives 12 to reduce a fuel supply load on tender car 14 (or forcontroller 48 of tender car 14 to reduce a rate of fuel supply to aparticular locomotive 12) based on a maintenance history or anotheridentification parameter (e.g., when a particular rail vehicle isnearing a required maintenance interval).

During operation of consist 10, controllers 48 may be configured tofurther adjust operation of their associated rail vehicles based onperformance data communicated between controllers 48 over the MU cable.For example, during a fault condition, different actions can be takendepending on which rail vehicle is generating the fault condition andwhat the fault condition is. Specifically, it may be possible for tendercar 14 to generate fault conditions of different criticality. The faultconditions can be generated manually or automatically based on one ormore conditions sensed by network components 50 (e.g., based on a fuellevel, a temperature, a pressure, a flow rate, a manually-pressed cutoffswitch, etc.). When the fault condition from tender car 14 is anon-critical fault condition, controllers 48 of locomotives 12 maysimply log the fault condition without further action being taken.However, when a more serious fault condition is communicated viaelectrical coupling 20, controllers 48 could alert the train operator,communicate the condition offboard to entity 52, reduce a consist speedand/or torque, adjust the blend ratio of fuels consumed by engines 28(i.e., reduce or increase consumption of gaseous fuel from tender car14), cause brakes to be applied, and/or implement other evasivemaneuvers. The reverse may also be true, wherein controller 48 of tendercar 14 selectively adjusts operation of pump 36, heat exchanger 38,accumulator 40, and/or regulator 42 based on fault conditions fromcontrollers 48 of locomotives 12 (e.g., based on fault conditions thatare triggered from sensed speeds, temperatures, pressures, etc. ofengines 28, generator 30, and/or associated wheel traction motors).

In some situations, it may be possible to generate the fault conditionsbased on communications between controller 48 of tender car 14 andcontrollers 48 of locomotives 12. For example, network components 50 ofa particular locomotive 12 may be capable of sensing or otherwisecalculating a fuel consumption rate of an associated engine 28 (e.g.,based on a measured flow rate, a measured speed of engine 28, a fuelsetting, etc.). Likewise, network components 50 of tender car 14 may becapable of sensing or otherwise calculating a rate of fuel supply to theengine 28 (e.g., based on a measured flow rate, a measured speed and/orpressure of pump 36, etc.). This information may then be communicatedbetween rail vehicles via electrical coupling 20 and, based on theinformation, one or more of controllers 48 may be able to detect asignificant difference between the fuel consumption and supply ratesthat is indicative of a fuel leak. When this occurs, a correspondingfault condition may be triggered causing operational adjustments of oneor more of the rail vehicles.

In another example, during a non-fault condition (i.e., during normaloperation), controllers 48 may still be configured to adjust operationof their associated rail vehicles based on performance data communicatedbetween controllers 48. For example, operation of locomotives 12 and/ortender car 14 may be adjusted based on the changing level of fuel withintanks 32 of locomotives 12 and/or within tank 34 of tender car 14. Thereare many reasons for doing so and many ways in which this can be done.Several exemplary situations are provided below.

In a first situation, it may be possible for locomotives 12 to havedifferent amounts of liquid fuel stored onboard within tanks 32 at anygiven time. For example, tank 32 of lead locomotive may be nearly fullof diesel fuel, while tank 32 of trail locomotive 12 b may be half full,and tank 32 of trail locomotive 12 c may be one-quarter full. In anideal situation, for emission purposes, each engine 28 of locomotives 12should be supplied with about the same blend of diesel fuel and naturalgas. However, such operation could cause trail locomotive 12 c tocompletely consume its supply of diesel fuel long before the otherlocomotives 12 consume their supplies. In this situation, it may bebetter for lead locomotive 12 a to operate with a higher diesel fuelblend and for trail locomotive 12 c to operate with a higher natural gasblend, such that all locomotives 12 can operate for an extended periodof time. Accordingly, based on fuel levels sensed by network components50 that are communicated between controllers 48 via access points 46 andelectrical coupling 20 (e.g., via the MU cable), each controller 48 mayselectively adjust the operation of its own associated rail vehicle. Theblend rate of fuel may be adjusted by changing an amount of diesel fuelsupplied to each engine 28 via control over onboard fuel supplycomponents and/or by changing an amount of natural gas provided to eachengine 28 from tender car 14 via control over pump 36, heat exchanger38, accumulator 40, and/or regulator 42.

In a second and related situation, the amount of natural gas storedwithin tank 34 of tender car 14 relative to the amounts of diesel fuelcontained within tanks 32 onboard locomotives 12 may be insufficient forthe expected duration of an intended trip at a desired fuel blend ratio.After communicating fuel level information between locomotives 12 andtender car 14, one or more of controllers 48 may determine the need toadjust the fuel blend such that the desired destination may be reachedwith the available fuel.

In a third situation, it may be more efficient for a locomotive 12located immediately adjacent to tender car 14 (e.g., trail locomotive 12b) to run at a higher natural gas blend than for a locomotive 12 locatedfurther away from tender car 14 (e.g., lead locomotive 12 a). Theimproved efficiency may be something that is sensed via networkcomponents 50, calculated by one or more of controllers 48, and/orsimply known based on past experience. Regardless of the way in whichthe improved efficiency is determined, any one or all of controllers 48may be configured to selectively adjust the blend rates of fuel suppliedto any one or more of engines 28.

In a fourth situation, it may be better for the engines 28 of particularlocomotives 12 to be loaded to a higher or lower degree than otherengines 28. For example, a particular engine 28 may operate moreefficiently when under a heavier load, as compared to a different engine28. Similarly, a particular engine 28 may operate at a more desirabletemperature under a given load. Other operational differences may alsoexist, and these communicated differences may be sensed via networkcomponents 50, calculated by controllers 48, or simply known based onpast experience, and then communicated between controllers 48. And basedon any of these differences, it may be desirable to selectively directmore or less natural gas from tender car 14 to a particular engine 28 ofa particular locomotive 12.

In a fifth situation, the demand for natural gas by a particularlocomotive 12 may simply change during a single trip and, unless thechanging demand is communicated to tender car 14, conditions of tendercar 14 may not be appropriate to comply with the change in demand.Specifically, when controller 48 of a particular locomotive 12communicates a change in demand for natural gas to controller 48 oftender car 14, controller 48 of tender car 14 may respond by adjustingoperation of its associated supply components. For example, controller48 of tender car 14 may adjust operation of pump 36, heat exchanger 38,accumulator 40, and/or regulator 42 based on the performance informationfrom locomotives 12 such that tender car 14 can supply natural gas atthe demanded level. It is contemplated that, in some instances, thechange in demand may be anticipated and communicated to controller 48 oftender car 14 in advance such that tender car 14 is immediately capableof supplying natural gas at the higher or lower rate when the new demandis received. The change in demand may be anticipated based on knownchanges in terrain, known restrictions on train speed at particulargeographic locations, and other known factors.

In a sixth and related situation, communication between tender car 14and locomotives 12 may have an effect on when locomotives 12 changetheir demand for natural gas. For example, it may be possible forcontrollers 48 of locomotives 12 to request a higher or lower supplyrate of natural gas, without yet commanding their associated engines 28to operate any differently. In response to the requested change insupply rate, controller 48 of tender car 14 may adjust operation of pump36, heat exchanger 38, accumulator 40, and/or regulator 42 in the mannerdescribed above. After making these adjustments, controller 48 of tendercar 14 may then inform controllers 48 of locomotives 12 that tender car14 is ready to supply natural gas at the higher or lower rate.Controllers 48 of locomotives 12 may be configured to only then commandengines 28 to operate differently.

In a seventh situation, it may be possible for a particular locomotivecontroller 48 to request a supply of natural gas from tender car 14 at arate that exceeds the capability of its associated engine 28 to consumethe natural gas. For example, based on pressures, temperatures, speeds,or other conditions sensed by network components 50 from onboard theparticular locomotive 12, controller 48 of tender car 14 may be able todetermine that the requested supply rate of fuel is too much. In thissituation, controller 48 of tender car 14 may be able to selectivelyreduce the supply rate. Similarly, it may be possible for a particularlocomotive controller 48 to request a supply of natural gas from tendercar 14 at a rate that exceeds the immediate capability of tender car 14to supply the fuel. In this situation, controller 48 of tender car 14may be able to request that the demand rate be temporarily reduced untiltender car 14 is capable of increasing its supply rate.

The disclosed communication system may improve control over tendercar/locomotive operations. Specifically, the enhance ability tocommunicate identification and operational information between tendercar 14 and locomotives 12 may allow consist 10 to operate moreefficiently and more responsively. That is, tender car 14 may be morecapable of supplying gaseous fuel to locomotives 12 in a manner and at atiming most beneficial to locomotives 12. At the same time, locomotives12 may be more capable of adjusting their own operations to accommodatecurrent operations and/or limitations of tender car 14. As a result,consist 10 may be have improved performance.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the disclosed system withoutdeparting from the scope of the disclosure. Other embodiments of thesystem will be apparent to those skilled in the art from considerationof the specification and practice of the system disclosed herein. It isintended that the specification and examples be considered as exemplaryonly, with a true scope of the disclosure being indicated by thefollowing claims and their equivalents.

What is claimed is:
 1. A method of communicating a locomotive with atender car, comprising: transmitting between the locomotive and thetender car operational data captured by network components locatedonboard at least one of the locomotive and the tender car; andselectively adjusting an operation of at least one of the locomotive andthe tender car based on the data.
 2. The method of claim 1, wherein theoperational data includes operational data captured by networkcomponents located onboard both of the locomotive and the tender car. 3.The method of claim 2, wherein the operational data includes at leastone of a speed, a load, a temperature, a flow rate, a pressure, and afuel level.
 4. The method of claim 1, wherein selectively adjusting anoperation includes selectively adjusting operation of an engine locatedonboard the locomotive.
 5. The method of claim 4, wherein selectivelyadjusting operation of the engine includes selectively adjustingoperation of at least one of a load on the engine, a fuel consumptionrate of the engine, a speed of the engine, and a blend ratio of fuelsupplied to the engine.
 6. The method of claim 5, wherein: thelocomotive is a first locomotive; the engine is a first engine; andtransmitting operational data includes transmitting operational databetween the first locomotive, a second locomotive, and the tender car;and selectively adjusting the operation includes selectively adjustingan operation of the first engine different than an operation of a secondengine located onboard the second locomotive.
 7. The method of claim 6,wherein: the operational data includes a level of liquid fuel storedonboard the first locomotive being different than a level of liquid fuelstored onboard the second locomotive; and selectively adjusting theoperation includes selectively adjusting a supply rate of gaseous fuelfrom the tender car to the first locomotive different than a supply rateof gaseous fuel from the tender car to the second locomotive based onthe different levels of liquid fuel stored onboard the first and secondlocomotives.
 8. The method of claim 6, wherein: the method furtherincludes determining a first distance between the first locomotive andthe tender car and a second distance between the second locomotive andthe tender car; and selectively adjusting an operation includesselectively adjusting a supply of gaseous fuel from the tender car tothe first and second engines differently based on the first and seconddistance.
 9. The method of claim 6, wherein: the method further includesdetermining a difference in operational performance between the firstand second engines; and selectively adjusting an operation includesselectively adjusting a supply of gaseous fuel from the tender car tothe first and second engines differently based on the difference inoperational performance.
 10. The method of claim 9, wherein thedifference in operational performance includes a difference in at leastone of efficiency and temperature.
 11. The method of claim 1, whereinselectively adjusting an operation includes selectively adjustingoperation of a least one of a pump, a heat exchanger, an accumulator,and a regulator located onboard the tender car.
 12. The method of claim11, wherein selectively adjusting operation includes selectivelyadjusting operation of at least one of a rate of fuel supply to anengine located onboard the locomotive and a fuel blend ratio.
 13. Themethod of claim 1, further including determining a fault condition basedon the operational data, wherein selectively adjusting an operationincludes selectively adjusting the operation only when the faultcondition is determined to be critical.
 14. The method of claim 13,further including communicating the fault condition to an offboardentity.
 15. The method of claim 1, wherein: the operational dataincludes a fuel consumption rate of the locomotive and a fuel supplyrate of the tender car; the method further includes determining fuelleakage based on a difference between the fuel consumption and supplyrates; and selectively adjusting includes selectively adjusting theoperation of at least one of the locomotive and the tender car based onthe fuel leakage.
 16. The method of claim 1, wherein: the operationaldata includes a level of liquid fuel stored onboard the locomotive and alevel of gaseous fuel stored onboard the tender car; the method furtherincludes determining an expected duration of an intended trop; andselectively adjusting the operation includes selectively adjusting ablend ratio of the liquid and gaseous fuel consumed by an engine of thelocomotive based on the level of liquid fuel, the level of gaseous fuel,and the expected duration.
 17. The method of claim 1, wherein:transmitting operational data includes transmitting from the locomotivea change in demand for gaseous fuel from the tender car; and selectivelyadjusting the operation includes selectively adjusting a supply rate ofgaseous fuel from the tender car to the locomotive based on the changein demand.
 18. The method of claim 17, wherein: transmitting the changein demand for gaseous fuel includes transmitting the change in demand inanticipation of a change in operation of an engine of the locomotive;and selectively adjusting includes selectively adjusting the supply rateof gaseous fuel from the tender car to the locomotive before the changein operation of the engine is implemented.
 19. The method of claim 18,wherein: transmitting operational data further includes transmitting areadiness of the tender car to supply gaseous fuel at rate correspondingto the change in demand; and the method further includes implementingthe change in operation of the engine only after the readiness of thetender car has been transmitted.
 20. The method of claim 18, furtherincluding anticipating the change in operation of an engine of thelocomotive based on at least one of a known change in terrain and aknown restriction on speed at a particular geographic location.
 21. Themethod of claim 17, further including: determining an ability of anengine on the locomotive to consume gaseous fuel in an amountcorresponding to the change in demand; and selectively reducing thechange in demand based on the ability.
 22. The method of claim 17,further including: determining an ability of the tender car to supplygaseous fuel in an amount corresponding to the change in demand; andselectively reducing the change in demand based on the ability.
 23. Amethod of communicating a locomotive with a tender car, comprising:transmitting identification information between the locomotive and thetender car; making a determination of an incompatibility between thelocomotive and the tender car based on the identification information;and generating an alert based on the determination.
 24. A method ofcommunicating a locomotive with a tender car, comprising: transmittingidentification information between the locomotive and the tender car;making a determination of a discrepancy between a capacity of thelocomotive and a capacity of the tender car based on the identificationinformation; and scaling future operation of at least one of thelocomotive and the tender car based on the determination.